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                  <a href="#GSeekable.description" class="shortcut">Description</a>
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                  <a href="#GSeekable.object-hierarchy" class="shortcut">Object Hierarchy</a>
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                  <a href="#GSeekable.prerequisites" class="shortcut">Prerequisites</a>
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                  <a href="#GSeekable.implementations" class="shortcut">Known Implementations</a>
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<h2><span class="refentrytitle"><a name="GSeekable.top_of_page"></a>GSeekable</span></h2>
<p>GSeekable — Stream seeking interface</p>
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<div class="refsynopsisdiv">
<a name="GSeekable.synopsis"></a><h2>Synopsis</h2>
<pre class="synopsis">
#include &lt;gio/gio.h&gt;

                    <a class="link" href="GSeekable.html#GSeekable-struct" title="GSeekable">GSeekable</a>;
struct              <a class="link" href="GSeekable.html#GSeekableIface" title="struct GSeekableIface">GSeekableIface</a>;
<a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="returnvalue">goffset</span></a>             <a class="link" href="GSeekable.html#g-seekable-tell" title="g_seekable_tell ()">g_seekable_tell</a>                     (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>);
<a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="GSeekable.html#g-seekable-can-seek" title="g_seekable_can_seek ()">g_seekable_can_seek</a>                 (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>);
<a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="GSeekable.html#g-seekable-seek" title="g_seekable_seek ()">g_seekable_seek</a>                     (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="type">goffset</span></a> offset</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-IO-Channels.html#GSeekType"><span class="type">GSeekType</span></a> type</code></em>,
                                                         <em class="parameter"><code><a class="link" href="GCancellable.html" title="GCancellable"><span class="type">GCancellable</span></a> *cancellable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Error-Reporting.html#GError"><span class="type">GError</span></a> **error</code></em>);
<a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="GSeekable.html#g-seekable-can-truncate" title="g_seekable_can_truncate ()">g_seekable_can_truncate</a>             (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>);
<a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            <a class="link" href="GSeekable.html#g-seekable-truncate" title="g_seekable_truncate ()">g_seekable_truncate</a>                 (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="type">goffset</span></a> offset</code></em>,
                                                         <em class="parameter"><code><a class="link" href="GCancellable.html" title="GCancellable"><span class="type">GCancellable</span></a> *cancellable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Error-Reporting.html#GError"><span class="type">GError</span></a> **error</code></em>);
</pre>
</div>
<div class="refsect1">
<a name="GSeekable.object-hierarchy"></a><h2>Object Hierarchy</h2>
<pre class="synopsis">
  GInterface
   +----GSeekable
</pre>
</div>
<div class="refsect1">
<a name="GSeekable.prerequisites"></a><h2>Prerequisites</h2>
<p>
GSeekable requires
 <a href="./../gobject/gobject/gobject-The-Base-Object-Type.html#GObject">GObject</a>.</p>
</div>
<div class="refsect1">
<a name="GSeekable.implementations"></a><h2>Known Implementations</h2>
<p>
GSeekable is implemented by
 <a class="link" href="GFileIOStream.html" title="GFileIOStream">GFileIOStream</a>,  <a class="link" href="GFileInputStream.html" title="GFileInputStream">GFileInputStream</a>,  <a class="link" href="GFileOutputStream.html" title="GFileOutputStream">GFileOutputStream</a>,  <a class="link" href="GMemoryInputStream.html" title="GMemoryInputStream">GMemoryInputStream</a> and  <a class="link" href="GMemoryOutputStream.html" title="GMemoryOutputStream">GMemoryOutputStream</a>.</p>
</div>
<div class="refsect1">
<a name="GSeekable.description"></a><h2>Description</h2>
<p>
<a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> is implemented by streams (implementations of 
<a class="link" href="GInputStream.html" title="GInputStream"><span class="type">GInputStream</span></a> or <a class="link" href="GOutputStream.html" title="GOutputStream"><span class="type">GOutputStream</span></a>) that support seeking.
</p>
</div>
<div class="refsect1">
<a name="GSeekable.details"></a><h2>Details</h2>
<div class="refsect2">
<a name="GSeekable-struct"></a><h3>GSeekable</h3>
<pre class="programlisting">typedef struct _GSeekable GSeekable;</pre>
<p>
Seek object for streaming operations.
</p>
</div>
<hr>
<div class="refsect2">
<a name="GSeekableIface"></a><h3>struct GSeekableIface</h3>
<pre class="programlisting">struct GSeekableIface {
  GTypeInterface g_iface;

  /* Virtual Table */

  goffset     (* tell)	         (GSeekable    *seekable);

  gboolean    (* can_seek)       (GSeekable    *seekable);
  gboolean    (* seek)	         (GSeekable    *seekable,
				  goffset       offset,
				  GSeekType     type,
				  GCancellable *cancellable,
				  GError      **error);

  gboolean    (* can_truncate)   (GSeekable    *seekable);
  gboolean    (* truncate_fn)    (GSeekable    *seekable,
				  goffset       offset,
				  GCancellable *cancellable,
				  GError       **error);

  /* TODO: Async seek/truncate */
};
</pre>
<p>
Provides an interface for implementing seekable functionality on I/O Streams.
</p>
<div class="variablelist"><table border="0">
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<tbody>
<tr>
<td><p><span class="term"><a href="./../gobject/gobject/gobject-Type-Information.html#GTypeInterface"><span class="type">GTypeInterface</span></a> <em class="structfield"><code><a name="GSeekableIface.g-iface"></a>g_iface</code></em>;</span></p></td>
<td>The parent interface.</td>
</tr>
<tr>
<td><p><span class="term"><em class="structfield"><code><a name="GSeekableIface.tell"></a>tell</code></em> ()</span></p></td>
<td>Tells the current location within a stream.</td>
</tr>
<tr>
<td><p><span class="term"><em class="structfield"><code><a name="GSeekableIface.can-seek"></a>can_seek</code></em> ()</span></p></td>
<td>Checks if seeking is supported by the stream.</td>
</tr>
<tr>
<td><p><span class="term"><em class="structfield"><code><a name="GSeekableIface.seek"></a>seek</code></em> ()</span></p></td>
<td>Seeks to a location within a stream.</td>
</tr>
<tr>
<td><p><span class="term"><em class="structfield"><code><a name="GSeekableIface.can-truncate"></a>can_truncate</code></em> ()</span></p></td>
<td>Chekcs if truncation is suppored by the stream.</td>
</tr>
<tr>
<td><p><span class="term"><em class="structfield"><code><a name="GSeekableIface.truncate-fn"></a>truncate_fn</code></em> ()</span></p></td>
<td>Truncates a stream.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="g-seekable-tell"></a><h3>g_seekable_tell ()</h3>
<pre class="programlisting"><a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="returnvalue">goffset</span></a>             g_seekable_tell                     (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>);</pre>
<p>
Tells the current position within the stream.
</p>
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<td><p><span class="term"><em class="parameter"><code>seekable</code></em> :</span></p></td>
<td>a <a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>the offset from the beginning of the buffer.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="g-seekable-can-seek"></a><h3>g_seekable_can_seek ()</h3>
<pre class="programlisting"><a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            g_seekable_can_seek                 (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>);</pre>
<p>
Tests if the stream supports the <a class="link" href="GSeekable.html#GSeekableIface" title="struct GSeekableIface"><span class="type">GSeekableIface</span></a>.
</p>
<div class="variablelist"><table border="0">
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<td><p><span class="term"><em class="parameter"><code>seekable</code></em> :</span></p></td>
<td>a <a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>
<a href="./../glib/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if <em class="parameter"><code>seekable</code></em> can be seeked. <a href="./../glib/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> otherwise.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="g-seekable-seek"></a><h3>g_seekable_seek ()</h3>
<pre class="programlisting"><a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            g_seekable_seek                     (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="type">goffset</span></a> offset</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-IO-Channels.html#GSeekType"><span class="type">GSeekType</span></a> type</code></em>,
                                                         <em class="parameter"><code><a class="link" href="GCancellable.html" title="GCancellable"><span class="type">GCancellable</span></a> *cancellable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Error-Reporting.html#GError"><span class="type">GError</span></a> **error</code></em>);</pre>
<p>
Seeks in the stream by the given <em class="parameter"><code>offset</code></em>, modified by <em class="parameter"><code>type</code></em>.
</p>
<p>
If <em class="parameter"><code>cancellable</code></em> is not <a href="./../glib/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error <a class="link" href="gio-GIOError.html#G-IO-ERROR-CANCELLED:CAPS"><code class="literal">G_IO_ERROR_CANCELLED</code></a> will be returned.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>seekable</code></em> :</span></p></td>
<td>a <a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset</code></em> :</span></p></td>
<td>a <a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="type">goffset</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>type</code></em> :</span></p></td>
<td>a <a href="./../glib/glib/glib-IO-Channels.html#GSeekType"><span class="type">GSeekType</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>cancellable</code></em> :</span></p></td>
<td>optional <a class="link" href="GCancellable.html" title="GCancellable"><span class="type">GCancellable</span></a> object, <a href="./../glib/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to ignore. <span class="annotation">[<acronym title="NULL is ok, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>error</code></em> :</span></p></td>
<td>a <a href="./../glib/glib/glib-Error-Reporting.html#GError"><span class="type">GError</span></a> location to store the error occurring, or <a href="./../glib/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to
ignore.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>
<a href="./../glib/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if successful. If an error
has occurred, this function will return <a href="./../glib/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> and set <em class="parameter"><code>error</code></em>
appropriately if present.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="g-seekable-can-truncate"></a><h3>g_seekable_can_truncate ()</h3>
<pre class="programlisting"><a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            g_seekable_can_truncate             (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>);</pre>
<p>
Tests if the stream can be truncated.
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>seekable</code></em> :</span></p></td>
<td>a <a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>
<a href="./../glib/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if the stream can be truncated, <a href="./../glib/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> otherwise.</td>
</tr>
</tbody>
</table></div>
</div>
<hr>
<div class="refsect2">
<a name="g-seekable-truncate"></a><h3>g_seekable_truncate ()</h3>
<pre class="programlisting"><a href="./../glib/glib/glib-Basic-Types.html#gboolean"><span class="returnvalue">gboolean</span></a>            g_seekable_truncate                 (<em class="parameter"><code><a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a> *seekable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="type">goffset</span></a> offset</code></em>,
                                                         <em class="parameter"><code><a class="link" href="GCancellable.html" title="GCancellable"><span class="type">GCancellable</span></a> *cancellable</code></em>,
                                                         <em class="parameter"><code><a href="./../glib/glib/glib-Error-Reporting.html#GError"><span class="type">GError</span></a> **error</code></em>);</pre>
<p>
Truncates a stream with a given <span class="type">offset</span>. 
</p>
<p>
If <em class="parameter"><code>cancellable</code></em> is not <a href="./../glib/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a>, then the operation can be cancelled by
triggering the cancellable object from another thread. If the operation
was cancelled, the error <a class="link" href="gio-GIOError.html#G-IO-ERROR-CANCELLED:CAPS"><code class="literal">G_IO_ERROR_CANCELLED</code></a> will be returned. If an
operation was partially finished when the operation was cancelled the
partial result will be returned, without an error.
</p>
<p>
Virtual: truncate_fn
</p>
<div class="variablelist"><table border="0">
<col align="left" valign="top">
<tbody>
<tr>
<td><p><span class="term"><em class="parameter"><code>seekable</code></em> :</span></p></td>
<td>a <a class="link" href="GSeekable.html" title="GSeekable"><span class="type">GSeekable</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>offset</code></em> :</span></p></td>
<td>a <a href="./../glib/glib/glib-Basic-Types.html#goffset"><span class="type">goffset</span></a>.</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>cancellable</code></em> :</span></p></td>
<td>optional <a class="link" href="GCancellable.html" title="GCancellable"><span class="type">GCancellable</span></a> object, <a href="./../glib/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to ignore. <span class="annotation">[<acronym title="NULL is ok, both for passing and for returning."><span class="acronym">allow-none</span></acronym>]</span>
</td>
</tr>
<tr>
<td><p><span class="term"><em class="parameter"><code>error</code></em> :</span></p></td>
<td>a <a href="./../glib/glib/glib-Error-Reporting.html#GError"><span class="type">GError</span></a> location to store the error occurring, or <a href="./../glib/glib/glib-Standard-Macros.html#NULL:CAPS"><code class="literal">NULL</code></a> to
ignore.</td>
</tr>
<tr>
<td><p><span class="term"><span class="emphasis"><em>Returns</em></span> :</span></p></td>
<td>
<a href="./../glib/glib/glib-Standard-Macros.html#TRUE:CAPS"><code class="literal">TRUE</code></a> if successful. If an error
has occurred, this function will return <a href="./../glib/glib/glib-Standard-Macros.html#FALSE:CAPS"><code class="literal">FALSE</code></a> and set <em class="parameter"><code>error</code></em>
appropriately if present.</td>
</tr>
</tbody>
</table></div>
</div>
</div>
<div class="refsect1">
<a name="GSeekable.see-also"></a><h2>See Also</h2>
<a class="link" href="GInputStream.html" title="GInputStream"><span class="type">GInputStream</span></a>, <a class="link" href="GOutputStream.html" title="GOutputStream"><span class="type">GOutputStream</span></a>
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